The IP Multimedia Subsystem (IMS) has come a long way from its origins in the third-generation (3G) standards organizations, where it was developed as a low-cost mechanism to add value to expensive radio access networks via modest services such as multimedia conferencing and push-to-share.

Now viewed as a generic control plane for all next-generation networks, IMS has become tightly coupled with voice over IP (VOIP) and fixed/mobile convergence. But for wireless mobile network operators looking to lift revenues, maintain profit margins, and stave off the commoditization of mobile voice, differentiated, revenue-generating IMS services remain elusive, finds the latest report from Unstrung Insider.

The report, Wireless IMS Services: Push-to-Revenue, examines infrastructure supplier and application developer strategies to catalyze the IMS services market, and investigates what types of IMS applications – broadly defined as services that involve simultaneous multimedia sessions – are most in demand by cellular network operators.

At the heart of wireless IMS strategies are new "foundation" services that any forward-looking operator or vendor simply has to offer – applications such as push-to-talk, push-to-share, instant messaging (IM) and presence in the consumer market, and Mobile IP Centrex in the enterprise sector. No doubt these services have appeal, and they should work better over IMS than they do today – but how hot are these applications really? From a mobile operator perspective, the actual subscriber uptake and revenue potential remains very much open to question.

Hence the push into fixed/mobile convergence: By making services – from basic voice and messaging to video sharing and music download – available across access networks and terminal types, mobile operators can rapidly expand their addressable market. Speaking about the recently announced Advanced-IMS (A-IMS) initiative (see A-IMS Effort Launched), Gerry Flynn, director of network strategy at Verizon Wireless was explicit that convergence is essential. "The target [IMS] architecture is access-agnostic," he said when interviewed for the report. "We have to interoperate with different access technologies."

But convergence alone is not enough – a phone call is a phone call, no matter how it is delivered – and IMS requires multiple new revenue-generating services to justify the up-front infrastructure investment. This means a long-term view of (and confidence in) the IMS services roadmap is critical for mobile network operators.

As a result, equipment vendors are being forced to step up their application development efforts. This not only helps their operator customers, but also gives them a competitive advantage in the critical services infrastructure layer. Scott Wharton, vice president of marketing at BroadSoft Inc. , says that in one current European IMS contract tender, his firm is the supplier of the IP Centrex application to five of the seven short-listed bidders – which is great for BroadSoft, but surely indicates a paucity of IMS services.

Turning this situation around from the vendor perspective typically involves a combination of in-house development, partnerships with independent software vendors, and most critically, initiatives that allow application developers from outside the telecom industry to use IMS as an underlying enabler for third-party services.

Marc LeClerc, manager of Ericsson AB (Nasdaq: ERIC)'s IMS Expert Center, says there are around 300 companies worldwide capable of Intelligent Network development, yet there are more than a million companies capable of IT-based application development. Clearly, the wireless industry needs to tap this source of innovation and creativity to stand a chance of making IMS live up to its potential.

The vendors that stand to benefit are those that best help their customers create new services (or even repackage old ones) through third-party developer support and testing programs.

— Gabriel Brown, Chief Analyst, Unstrung Insider

The report, Wireless IMS Services: Push-to-Revenue, is available as part of an annual subscription (12 monthly issues) to Unstrung Insider, priced at $1,595. Individual reports are available for $900. To subscribe, please visit: www.unstrung.com/insider.